AC blowing cold air but house won’t cool

Old 07-09-19, 11:58 PM
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AC blowing cold air but house won’t cool

Hi everyone. I’m a relatively new home owner and new to the forum. I’m having some serious cooling issues and am not having much luck with AC techs.

i purchased the house in October and experienced no cooling problems until recently. Now I also happened to install skylights in my living room in May but they are high end energy efficient velux with solar powered blinds. I was concerned it would heat the house but assumed the effect would be minimal.

Fast forward to july and I the house won’t cool below 80 degrees until maybe 4-5am. Then it climbs back up regardless of the temp it’s set at. I have kept the skylight blinds closed all day and night and it doesn’t make a difference. The blinds are thick heavy duty fabric with aluminum and they block out all light.

when I investigated my handler I noticed massive amounts of sweat and condensation. I initially was worried I had a clogged drain line so I went to look for the exterior clean out and it didn’t exist. The tech that came also was never able to find it. He did however determine that I was low on refrigerant and filled it back up. A week or two passed and it was still an issue so he came back out and determined there was a leak of refrigerant and repaired that. Now two weeks later and It feels even worse at night. He came back out and said there is nothing wrong with the unit and it is blowing cold air.

i can’t imagine that this is only because of the skylights but I am not sure what else to blame it on. I had skylights in my last house that were ancient and I never experienced anything like this. The tech even said it should be cooling regardless of the sky lights. The condenser is fine and the unit is relatively new- only a couple of years. The tech did say that I had ‘old brown insulation’ but this didn’t seem to be an issue in the spring.

Does anyone have any any thoughts or advice? I really appreciate the help.


Last edited by Pmperceval; 07-10-19 at 12:06 AM. Reason: Forgot to add a detail
Old 07-10-19, 03:38 AM
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No doubt the skylights created additional paths for sunlight to heat the inside of the house. Temperatures in October are cooler than temperatures in July so the load on the A/C is greater in July. Since this is the first July in the home, the lack of sufficient cooling in the summer may indicate the A/C is too small for the size of the house. While it may be a new condition for you, it may not be for the house. Get a reputable A/C company to come out and determine the size of A/C required and go from there.
Old 07-10-19, 06:34 PM
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Welcome to the forums.

You left out your location. That's important in a discussion like this.
The outside condenser on the hot side of the house can be a problem.

Is your house shaded from the sun ?
Do you get good airflow from the registers ?

You can do a basic check to see how well the system is performing. Get an accurate thermometer and measure the cold air coming out of the closest register to the air handler. Then measure the air entering the return. It's usually best to measure at the air handler but you can't always access it. You could measure at several returns and average them. The difference between the two temps can be a basic guidline for performance. Typically at least a 20 degree difference is good.

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